package PTA;

import java.util.LinkedList;
import java.util.Scanner;

class Stack<T> {
    private LinkedList<T> List = new LinkedList<T>();
    public void push(T e) {
    	List.addFirst(e);
    }
    public T peek() {
        return List.getFirst();
    }
    public T pop() {
        return List.removeFirst();
    }
    public boolean empty() {
        return List.isEmpty();
    }
}


public class Main201621123002 {
    public static void main(String[] args) {
    	Scanner in=new Scanner(System.in);
        Stack<Character> stack = new Stack<Character>();
        String string = in.nextLine();
        for (int i = 0; i < string.length(); i++) {
            stack.push(string.charAt(i));
        }
        boolean flag = true;
        for (int i = 0; i < string.length(); i++) {
            if (stack.pop() != string.charAt(i)) 
            {
                flag = false;
                break;
            }
        }
        if (flag) 
            System.out.println("yes");
        else
            System.out.println("no");
    }
}